OData Service GUID issue - Conversion error for property MATID at offset 256

Hi All,

I am using MATID field in Entity of a OData service and it is set to type EDM.GUID. This field is not a key field and set to NULL possible checkbox.

When I am passing payload in gateway client for CREATE_DEEP_ENTITY operation, I get error : Conversion error for property MATID at offset 256

If I skip passing this field in OData payload and perform POST operation, it works fine. Can anyone suggest how to get rid of this error. I tried passing both of below format values for MATID but it does not work. Kindly help